CVE-2023-54108

Root

Cause A DMA-API call trace warning was observed in the Linux kernel's qla2xxx driver during NVMe LS (Login Service) requests. The trace indicated that the device driver failed to check a map error before unmapping, leading to a kernel warning. The issue stemmed from the driver performing its own DMA mapping of NVMe LS request data, even though the FC (Fibre Channel) layer already handles this mapping.

Exploitation

Scenario This vulnerability does not represent a security flaw exploitable by an attacker; rather, it is a kernel bug that causes a warning message under certain I/O workloads. No special privileges or network access are required beyond normal system operation, and the impact is limited to a kernel warning and potential debug overhead.

Impact

The primary impact is a kernel warning message and a stack trace, which may degrade system performance due to debug logging and cause unnecessary alarm. In non-debug kernels, the warning is silently suppressed, so the functional impact is minimal. The driver continues to operate, but the redundant DMA mapping could lead to resource leaks or memory corruption in edge cases.

Mitigation

The fix removes the redundant DMA mapping from the qla2xxx driver, relying entirely on the FC layer's mapping. Patches have been committed to the stable Linux kernel trees [1][2]. Users should apply these patches or update to a kernel version containing the fix. No workaround is available other than avoiding NVMe LS operations or using a patched kernel.